This disclosure generally relates to a heat transfer fluid, additive package, system, and method.
The operation of a power source generates heat. A heat transfer system, in communication with the power source, regulates the generated heat by absorbing and dissipating the heat from the power source. A gasoline powered internal combustion engine, for example, powers an automotive vehicle. Heat transfer fluids and systems dissipate the heat generated as a by-product of gasoline combustion, and ensure that the engine operates at an optimum temperature. Heat transfer fluids, which generally comprise water or a glycol, are in communication with one or several metallic parts that are prone to corrosion. Thus, several corrosion inhibitors are added to the heat transfer fluid in order to protect the metallic parts from corrosion.
Several power sources alternative to internal combustion engines, including but not limited to batteries, fuel cells, solar or photovoltaic cells, and internal combustion engines powered by the condensation of steam, natural gas, diesel, bio diesel, alcohol, bio alcohol, hydrogen, and/or the like, also benefit from heat transfer fluids and systems. Alternative power sources can be used alone or in combination, such as in hybrid vehicles or other non-vehicle applications.
Aluminum is an example of a metal, that, along with its alloys, can be used in the manufacture of several components of the heat transfer system such as radiators, condensers, evaporators, heater cores, intercoolers, charge air coolers, oil coolers, heat exchangers, water pumps, flow channels, engine blocks, and the like.
Magnesium alloys have a high strength-to-weight ratio. Use of magnesium alloys in automobiles has been increasing due to the need of increasing fuel economy, reducing pollution and lessening dependence on petroleum. Several magnesium alloy applications in various parts of vehicles have been developed, including, but not limited to, oil pans, gearbox housings, and radiator support assemblies. However, use of magnesium alloys for vehicle powertrain systems, such as engine blocks, and for parts of a heat transfer system, has been quite limited to date. One limitation may be attributed to their poor corrosion resistance when they are in contact with the heat transfer fluids commonly used in heat transfer systems. The use of magnesium alloys in alternative power sources shares similar corrosion related drawbacks.
The aluminum and magnesium can be prone to corrosion, such as, but not limited to, cavitation corrosion, erosion corrosion, cavitation erosion corrosion, halogen based flux residue induced corrosion, galvanic corrosion, pitting corrosion, crevice corrosion, and the like. Several types of corrosion inhibitors have been identified to address the foregoing corrosions, such as organic acids, silicates, organic acid/silicate hybrids, and the like. However, common corrosion inhibitors suffer from certain drawbacks such as, but not limited to, depletion of the active corrosion inhibitor over time, excessive foaming in certain components (for example, in a water pump) which leads to premature failure due to cavitation and erosion corrosion, and lack of compatibility with different corrosion-prone metals.
Thus, there exists a need for heat transfer fluids that provide improved corrosion resistance to several metals, such as, but not limited to, aluminum and magnesium, while reducing foaming tendencies that can adversely affect components in a heat transfer system. In addition, there is an ongoing interest in corrosion inhibitors with improved corrosion inhibiting properties, and other advantageous properties such as anti-foaming, or low foaming tendency, and the like.